Efavirenz, Oral

What are other names for this medicine?

Type of medicine: antiviral

Generic and brand names: efavirenz, oral; Sustiva

What is this medicine used for?

This medicine is taken by mouth to treat HIV-1 infection. It is usually taken with other medicines. This medicine comes in tablet and liquid forms.

What should my health care provider know before I take this medicine?

Tell your health care provider about any history of mental illness or substance abuse, and any other medical conditions you may have, including diabetes, heart disease, high cholesterol, bleeding disorders, liver disease, or kidney disease.

Females of childbearing age: Tell your health care provider if you are pregnant or plan to become pregnant. Do not breast-feed while taking this medicine without your health care provider's approval.

How do I take it?

Take this medicine exactly as your health care provider prescribes. Do not change your dosage on your own. Do not stop taking this medicine without your health care provider's approval. If you are not sure of how much and how often to take this medicine, ask your health care provider or pharmacist to explain.

Take this medicine with other medicines your health care provider prescribes. Follow your health care provider's instructions exactly.

Do not take this medicine with meals that are high in fat.

Do not miss any doses. If you do miss a dose, take it as soon as you remember unless it is almost time for the next scheduled dose. In that case, skip the missed dose and take the next one as directed. Do not take double doses. If you are not sure of what to do if you miss a dose, or if you miss more than one dose, contact your health care provider.

What should I watch out for?

Allergic reactions (some fatal) have occurred with this medicine. If you develop a fever, rash, itching all over, nausea, vomiting, diarrhea, abdominal pain, or trouble breathing, stop taking the medicine and contact your health care provider or get emergency medical care right away.

If you need emergency care, surgery, or dental work, tell the health care provider or dentist you are taking this medicine.

When taken with this medicine, alcohol and other drugs may make you dizzier and drowsier than usual. Discuss this with your health care provider.

This medicine may cause dizziness, trouble concentrating, depression, or drowsiness. These symptoms often go away as your body adjusts to the medicine. Taking this medicine at night may help to make these symptoms less bothersome. Do not drive or operate machinery unless you are fully alert.

You may develop a rash. This usually goes away without any change in treatment. Occasionally, the rash becomes serious. Report any rash to your health care provider right away, especially if it lasts for more than 2 days.

This medicine is not a cure for HIV infection. You may continue to get illnesses associated with advanced HIV infection, including other infections. There is no evidence that this medicine will reduce the risk of spreading HIV through sexual contact or blood contamination.

What are the possible side effects?

Along with its needed effects, your medicine may cause some unwanted side effects. Some side effects may be very serious. Some side effects may go away as your body adjusts to the medicine. Tell your health care provider about any side effects that continue or get worse.

Serious (report these your health care provider right away): Dizziness, drowsiness, abnormal dreams, or depression that does not go away; serious rash with a fever, blistering, mouth sores, red eyes, swelling, muscle pain or joint pain.

Other: Numbness, indigestion, stomach pain, gas, diarrhea, loss of appetite, or bloody urine.

What products might interact with this medicine?

When you take this medicine with other medicines, it can change the way this or any of the other medicines work. Nonprescription medicines, vitamins, natural remedies, and certain foods may also interact. Using these products together might cause harmful side effects. Talk to your health care provider if you are taking:

• antibiotics such as clarithromycin (Biaxin), erythromycin (EryC, Ery-Tab, E.E.S., Erythrocin), and sulfamethoxazole/trimethoprim (Bactrim, Bactrim DS, Septra, Septra DS)
• birth control pills (talk to your health care provider if you need birth control)
• blood thinners such as warfarin (Coumadin), clopidogrel (Plavix), ticlopidine (Ticlid), heparin, and aspirin
• cisapride (Propulsid)
• ergot medicines such as dihydroergotamine (D.H.E. 45), ergotamine (Ergomar), ergonovine (Ergotrate), and methylergonovine (Methergine)
• indinavir (Crixivan)
• nelfinavir mesylate (Viracept)
• rifabutin (Mycobutin)
• rifampin (Rifadin, Rimactane)
• ritonavir (Norvir)
• saquinavir (Invirase, Fortovase).
• sedatives such as alprazolam (Xanax), diazepam (Valium), lorazepam (Ativan), chlordiazepoxide (Librium), clorazepate (Tranxene), estazolam (ProSom), flurazepam (Dalmane), midazolam (Versed), zolpidem (Ambien), and triazolam (Halcion)
• vitamins.

The effects of this medicine may be increased if you take it with grapefruit juice. Discuss this with your health care provider.

Keep a list of all your medicines (prescription, nonprescription, supplements, natural remedies, and vitamins) with you. Be sure that you tell all health care providers who treat you about all the products you are taking.

This advisory includes selected information only and may not include all side effects of this medicine or interactions with other medicines. Ask your health care provider or pharmacist for more information or if you have any questions.

Ask your pharmacist for the best way to dispose of outdated medicine or medicine you have not used. Do not throw medicine in the trash.

Keep all medicines out of the reach of children.

Do not share medicines with other people.